I have been to the doctor a couple of times,and they noticed my heart beats fast like as if I am anxious. At first I thought it could be because I was anxious to be at the docor, or the red bulls I was drinking, but I have been watching it closely and notice it is all the time. Could something be wrong? I get sharp pains in my chest, but I do have asthma so can't determine if it is from that or my heart. What should I do? Is there any precautions I should take?

First we have to determine what you mean by "fast." Have you actually taken your pulse and determined the rate? Anything between 60 and 100 can be considered normal. If you're drinking Red Bull on a regular basis this will certainly increase your heart rate over whatever may be normal for you. It's best to check your pulse while sitting, relaxed, and also best to count it for 15 seconds and multiply the number of beats in that period by 4 to get the correct total. It's going to be faster at certain times of the day, during certain activities, during stress, and when caffeine is ingested. Red Bull has lots of caffeine.

Sharp chest pains are almost always muscular in nature and not heart-related. Asthma can often cause these because of straining of accessory muscles while breathing.

Please let us know what you consider a "fast" heart rate and we can go from there. I hope this is helpful. Good luck to you.